DURING COP21 IN PARIS INTERNATIONAL GOVERNMENTS HAVE AGREED TO PRODUCE ROBUST ESTIMATES OF FOREST CARBON STOCKS FOR SUCCESSFUL IMPLEMENTATION OF CLIMATE CHANGE MITIGATION POLICIES RELATED TO REDUCING EMISSIONS FROM DEFORESTATION AND DEGRADATION (REDD). THE CLIMATE AGREEMENT INDICATES THAT THE TROPICAL COUNTRIES MAY RECEIVE TECHNICAL AND SCIENTIFIC SUPPORT TO ACHIEVE THEIR NATIONAL MITIGATION GOALS AND FOR THEIR POST2020 CLIMATE ACTIONS. IN ANTICIPATION TO THESE CLIMATE AGREEMENTS AND THE URGENT NEED FOR IMPROVED MAPPING OF GLOBAL FOREST ABOVEGROUND LIVE BIOMASS AND THE LACK OF ANY EXISTING SPACEBORNE SYSTEMS CAPABLE OF ADDRESSING THIS NEED THE BIOMASS P-BAND SYNTHETIC APERTURE RADAR (SAR) MISSION WAS PROPOSED TO THE EUROPEAN SPACE AGENCY FOR THE THIRD CYCLE OF EARTH EXPLORER CORE MISSIONS AND WAS SELECTED IN 2013 AND IT WILL BE LAUNCHED IN 2020-21. THE OBJECTIVES OF THE MISSION ARE 1) TO QUANTIFY THE MAGNITUDE AND DISTRIBUTION OF FOREST BIOMASS GLOBALLY AND 2) TO MONITOR AND QUANTIFY CHANGES IN TERRESTRIAL FOREST BIOMASS GLOBALLY ON AN ANNUAL BASIS OR BETTER LEADING TO IMPROVED ESTIMATES OF TERRESTRIAL CARBON SOURCES (PRIMARILY FROM DEFORESTATION) AND TERRESTRIAL CARBON SINKS DUE TO FOREST REGROWTH AND AFFORESTATION. NASA HAS ALSO SELECTED GEDI (GLOBAL ECOSYSTEM DYNAMIC INVESTIGATION) AS A LIDAR SAMPLING SENSOR ABOARD THE INTERNATIONAL SPACE STATION FOR QUANTIFYING FOREST STRUCTURE. GEDI WILL BE LAUNCHED IN 2018-2019 AND WILL COLLECT DATA FOR 12-18 MONTHS. NASA-ISRO SAR (NISAR) INSTRUMENT FOR MAPPING VEGETATION BIOMASS IN AREAS OF LOW BIOMASS DENSITY (&LT;100 MG/HA) IS ANOTHER NASA MISSION USING L-BAND AND S-BAND SAR SYSTEMS SELECTED FOR LAUNCH IN 2020-21 PERIOD. TOGETHER THESE SENSORS ARE CAPABLE OF SIGNIFICANTLY IMPROVING THE STATE OF VEGETATION CARBON STOCKS AND CHANGES GLOBALLY. WE PROPOSE TO DEVELOP AND VALIDATE FOREST BIOMASS ESTIMATION ALGORITHMS USING THREE BIOMASS MISSION P-BAND RADAR MEASUREMENTS:1) POLARIMETRIC BACKSCATTER (POLSAR) 2) POLINSAR AND 3) TOMOSAR FOR QUANTIFYING FOREST ABOVEGROUND STRUCTURE. WE WILL FOCUS ON TROPICAL FOREST ECOSYSTEMS WHERE THE BIOMASS MISSION WILL HAVE THE BEST SENSITIVITY AND COVERAGE TO QUANTIFY FOREST STRUCTURE. FOR ALGORITHM TRAINING AND VALIDATION WE WILL HAVE ACCESS TO EXTENSIVE GROUND AND AIRBORNE MEASUREMENTS OVER DIFFERENT TROPICAL FORESTS AS PART OF EXISTING AND PLANNED ESA AND NASA S JOINT CAMPAIGNS FOR THE THREE MISSION SYNERGISTIC PRODUCTS AND VALIDATION. BOTH SASSAN SAATCHI AND HERMAN SHUGART HAVE PARTICIPATED IN THE BIOMASS MISSION ADVISORY BOARD AS EXTERNAL OBSERVERS FOR MORE THAN 5 YEARS. SASSAN SAATCHI WAS PART OF THE ORIGINAL PROPOSAL TEAM FOR THE BIOMASS MISSION AND HAS HELPED DEVELOPING THE MISSION SCIENCE AND MEASUREMENT REQUIREMENTS AND HAS CONTRIBUTED IN DESIGNING OF THE BIOMASS OBSERVATIONAL CHARACTERISTICS TO MEET THE SCIENCE REQUIREMENT. THIS PROPOSED RESEARCH WILL PROVIDE THE US TEAM MEMBERS THE OPPORTUNITY TO FORMALLY CONTRIBUTE TO THE DEVELOPMENT AND VALIDATION OF THE SCIENCE ALGORITHMS AND THE PRODUCTION OF SCIENCE PRODUCTS OVER TROPICAL FORESTS.